Overview
The Joint Committee Concerning Digital Terrestrial Broadcasting, comprising
the Ministry of Posts and Telecommunications (MPT), commercial broadcasters
and NHK, gave its unanimous approval this April on the digital channels
needed nationwide for the master stations and is scheduled to reach
a consensus on large-scale relay stations by the end of 2001. At a Joint
Committee meeting on April 26, a consensus was reached on the digital
terrestrial broadcasting master station channel plan and on the expenses
involved in the analog broadcasting channel changes. The basic implementation
plans were also agreed in the meeting.
In order to secure the necessary channels for digital broadcasting in
the congested frequency environment of Japan, analog channel changes
are unavoidable. One of the main issues in establishing the digital
channel plan is to minimize the influence caused by the analog channel
changes.
With the channel changes for master stations as planned in the report
issued on April 26, it is estimated that the number of households affected
will be 2.46 million and the countermeasure budget will reach 85.2 billion
yen. In these estimations, the channel plan calculates the number of
households affected on the supposition that there should be approximately
450 digital stations with more than 30W transmission power.
Implementation Plan
The basic implementation plans on which the Joint Committee has agreed
are as follows;
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The government should bear the expense of countermeasures associated
with analog channel changes. |
* |
The DTB services shall be started in three of Japan's largest
urban areas (Tokyo, Osaka and Nagoya) by the end of 2003, and in
nationwide master stations by the end of 2006. The current analog
services shall be terminated by around 2010. |
* |
In order to ensure efficient spectrum use, part of the UHF-band
shall be returned to the government after the transition from analog
to digital is completed. |
* |
The transition to digital broadcasting should be done at the lowest
possible cost. |
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Figure 1: Organization of the Joint Committee |
The Present Status of Digital Terrestrial Test Broadcasting
(1) Pilot Test
Moving toward the introduction of digital terrestrial broadcasting,
each 'Regional Test Consortium' in eleven zones throughout Japan
has been conducting test broadcasting. Transmission stations in
some areas also have relay stations so that the functions of SFN
can be verified. All these eleven zones are equipped such that
they can perform experiments on data broadcasting as well as HDTV
and SDTV broadcasting.
In the greater Tokyo area, test signals are emitted on UHF channel
15 (transmission power: 100 W). The Tokyo Pilot (one of the eleven
regional test consortiums) ran checks on radio reception, especially
the characteristics of transmission paths, for fixed and mobile
receivers during the first half of 1999. In the second half of
the year, it conducted experiments on the transmission and reception
of data as well as video and audio signals. In these experiments,
program guides and program information such as recipes for a cooking
program were aired as data.
(2) Experiment for the Kyushu/Okinawa
Summit Meeting
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Figure 2: Pilot Broadcast Areas in Japan
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The world's leading nations convened in Okinawa and Kyushu in
July this year. To cover this summit, NHK conducted experiments
on digital terrestrial broadcasting as well as digital satellite
broadcasting from July 7 to 23. These experiments included a digital
HDTV broadcasting service that provided high-resolution pictures
and dynamic sound as well as SDTV services for mobile reception
(for cars and other moving objects).
NHK installed radio receivers at fifteen sites, including the press
center and hotels where the world's leaders were staying. These
receivers were used to introduce Japan's digital terrestrial broadcasting
services to the world's leaders and the press. Similar receivers
were set up at 24 points throughout Okinawa so that digital terrestrial
broadcasts could be viewed by the general public as well. |
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